Spinward Flow
SOC-14 5K
My understanding is that Social A amounts to "planetary nobility" of the this family is a bunch of nobles on a planetary scale where they're the biggest fish in the "small pool" of a single world. Once you get to Social B+ is when you start getting interstellar on your nobility.SOC A (and above) is the point at which an individual is part of the Imperial Nobility "in-group" and can be assumed to benefit from its interstellar institutions (cultural, social, and in this case, medical).
The actual Noble career path is what puts people/characters "in post" as Imperial Nobles responsible for worlds ... but not immediately. First you have to earn Position (per LBB S4, and not guaranteed) and THAT is what puts your character "in post" as an Imperial Noble with world-wide responsibilities.
Kind of like how if you roll up an Imperial Navy character and they make Admiral, if they're given Command assignments as an Admiral they're going to be commanding an Imperial Fleet (somewhere). Same deal for the Noble career ... except that you need to earn Position first. If you're Social A-B this means that your character becomes the Knight of {fill in the blank} world (and for Social A is an automatic promotion to Social B as a Knight). At Social C you become Baron of {fill in the blank} world ... and so on.
Pretty much every Imperial mainworld has a Knight of {fill in the blank} assigned to it.
Barons get assigned to Agricultural or Rich worlds.
Marquis get assigned to pre-Industrial worlds.
Counts get assigned to Industrial worlds with a county of sub-worlds below the subsector governing level.
Dukes get assigned to subsector capitals, with one of them rising to the level of Sector Duke (in a first among equals kind of way).
Archdukes have responsibilities for entire Domains (multi-sector).
Beyond that you get into the imperial family (prince/princess, emperor/empress).
I always figured that the extreme difficulty of getting promoted in the Noble career was largely due to the fact that as you climb the (social) ladder, there are fewer and fewer "open posts" for your character to fill, so there is most definitely a "winnowing of the chaff" going on in terms of limited opportunities for advancement. It's basically a case of roll 12 on 2D (+1 DM if Intelligence A+) in order to get promoted to the next rank. Any promotion above Social C will typically involve moving to a new world(!). You can go from Knight to Baron on the same world, but probably won't get to "stay put" if promoted from Baron to Marquis while in the Noble career.